Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredAbstract
Namespace Prefix:	al_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences after the fifth fiscal year following the latest fiscal year.

No definition available.

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredAfterFifthYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences in the fifth fiscal year following the latest fiscal year.

No definition available.

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInFifthYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences in the fourth fiscal year following the latest fiscal year.

No definition available.

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInFourthYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

No definition available.

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInRemainderOfFiscalYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences in the second fiscal year following the latest fiscal year.

No definition available.

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInSecondYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences in the third fiscal year following the latest fiscal year.

No definition available.

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredInThirdYear
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of new aircraft that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences.

No definition available.

Name:	al_LongTermPurchaseCommitmentMinimumQuantityRequiredNewAircraft
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of long-range variants.

No definition available.

Name:	al_NumberOfLongRangeVariants
Namespace Prefix:	al_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Minimum amount of purchase arrangement maturing in the remainder of fiscal year.

No definition available.

Name:	al_PurchaseObligationDueInRemainderOfFiscalYear
Namespace Prefix:	al_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Carrying amount, at the balance sheet date, of deposits made to the manufacturer for new flight equipment still under construction. May include capitalized interest.

No definition available.

Name:	us-gaap_DepositsOnFlightEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_LongTermPurchaseCommitmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences.

No definition available.

Name:	us-gaap_LongTermPurchaseCommitmentMinimumQuantityRequired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

No definition available.

Name:	us-gaap_PurchaseObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Minimum amount of purchase arrangement maturing after the fifth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

No definition available.

Name:	us-gaap_PurchaseObligationDueAfterFifthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Minimum amount of purchase arrangement maturing in the fifth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

No definition available.

Name:	us-gaap_PurchaseObligationDueInFifthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Minimum amount of purchase arrangement maturing in the fourth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

No definition available.

Name:	us-gaap_PurchaseObligationDueInFourthYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Minimum amount of purchase arrangement maturing in the second fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

No definition available.

Name:	us-gaap_PurchaseObligationDueInSecondYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Minimum amount of purchase arrangement maturing in the third fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments.

No definition available.

Name:	us-gaap_PurchaseObligationDueInThirdYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_PurchaseObligationFiscalYearMaturityAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AircraftsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_CounterpartyNameAxis=al_AirbusMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA320321200Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA320321NEOMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA321neoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_A320200Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_A330800900neoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA3509001000Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_AirbusA3501000Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_B737800Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_Boeing73789MAXMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_B777300ERMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_B787910Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=al_ATR72600Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: